One popular type of window covering is known as a Roman shade. This type of shade consists of a fabric material attached along its top edge to a headrail and gathered at spaced intervals to provide a series of soft folds across the face of the fabric. Consequently, the Roman shade has a cascaded or softly pleated appearance.
The most common practice for making a Roman shade is to sew at least two sets of rings or connectors along vertical lines down the back of the fabric material such as is shown in U.S. Pat. No. 1,321,800. In one type of Roman shade a lift cord passes from the headrail through each set of rings and may either be fastened to the bottom edge of the fabric or loop around the bottom edge of the fabric up the front face of the fabric and return to the headrail. In another type of Roman shade, each set of connectors is both sewn to the fabric and attached to a cord at spaced apart intervals along the cord. The interval between spacers on each cord may be equal to or less than the distance between the points at which the spacers are attached to the back of the fabric.
Because it takes a substantial amount of time to sew connectors to the back of the fabric for a Roman shade, the art has developed other ways to connect the fabric to the cord. In the window covering disclosed in U.S. Pat. No. 4,694,545 a set of U-shaped filaments are inserted through the fabric from the front. The ends of each filament are gathered in a tube, bent over the end of the tube and held in place by a sleeve that fits over the tube. This system has a large number of small pieces. Most shade fabricators prefer not to use systems that have large numbers of small parts that must be assembled.
The art has also utilized one or more transverse ribs to provide support or maintain spacing between the cords which are oriented vertically across the back of the fabric. Examples of such ribs are shown in U.S. Pat. No. 5,207,256 wherein the ribs are placed within spaced apart transverse pockets in the fabric. In this system the pockets must be sewn into the material.
Thomsen et al. in U.S. Pat. No. 5,273,096 disclose a shade in which a set of parallel rods are placed on one side of the fabric. A tubular member having a longitudinal opening fits over each rod gripping the fabric therebetween. Loops are provided on the tubular members through which lift cords pass. If this system is used on a Roman shade for a large window the tube and rod combinations will add substantial weight to the shade. Moreover, the tubes and rods add substantial cost to such a shade.
There is a need for a light weight Roman shade which can be quickly assembled by the fabricator. The shade should have a spacer system that can be connected to the fabric without sewing and is both light weight and inexpensive.